Potential Medical Complications
Buildup of fluid in the brain
(3 to 5 years)
What is it?
Increased pressure in the brain due to a buildup of fluid (also called hydrocephalus). In some children, increased pressure may come and go.
Possible symptoms
- Sudden increase in head size or disproportionately large head (on the achondroplasia-specific growth chart)
- Bulging or stiff “soft spot” of head (the soft spot can stay open until 5 to 6 years in age in children with achondroplasia)
- Tiredness and/or irritability
- Headache
- Prominent veins on the scalp and skull
- Vomiting
These are not all the symptoms of hydrocephalus. Sometimes, there are no signs or symptoms. Some of these symptoms may indicate another disease or condition. Only a doctor can diagnose hydrocephalus. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis may involve measurements of head circumference, a neurological examination, fast magnetic resonance imaging (MRI) conducted in both flexion and extension positions, a computed tomography (CT) scan, and/or intracranial pressure monitoring.
Treatment is given by a pediatric neurosurgeon. About 4% of children will require surgery to place a tube, or shunt, into the brain to drain the extra fluid.
Narrowing at the base of the skull
(3 to 5 years)
What is it?
Narrowing of the opening at the base of the skull (also called foramen magnum stenosis), which may cause squeezing of the nerves or blood vessels.
Possible symptoms
- Muscle weakness that lasts a long time
- Asymmetric resistance, strength, and reflexes
- Involuntary muscle contractions in the ankles
- Abnormal toe movement when stroking the bottom of the foot (Babinski reflex)
- Fatigue and decreased endurance
- Pain in the arms and legs that is sudden and comes and goes
- Decreased fine motor skills
- Bowel and bladder incontinence
These are not all the symptoms of foramen magnum stenosis. Some of these symptoms may indicate another disease or condition. Only a doctor can diagnose foramen magnum stenosis. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis is made by a pediatric neurosurgeon and may include a neurologic examination, magnetic resonance imaging (MRI) conducted in both flexion and extension positions, and a computed tomography (CT) scan.
Treatment involves a surgical procedure called cervicomedullary decompression (CMD) to relieve pressure on the nerves at the base of the skull. Less than 5% of children between ages 3 and 5 years will need surgery.
Due to an increased risk of injury to the spinal cord from forceful head movements, it is recommended to keep your child in a rear-facing car seat for as long as tolerated.
Obstructive sleep apnea
(3 to 5 years)
What is it?
Breathing repeatedly stops and starts during sleep due to blockage of the upper airway. This blockage may result from a narrow airway, a flat basal bridge, weak breathing muscles, and/or enlarged adenoids and tonsils. Affects up to 75% of children with achondroplasia.
Possible symptoms
- Gasping sounds during sleep
- Frequent wake-ups or restless sleep
- Daytime sleepiness
- Difficulty paying attention
- Hyperactivity
- Poor academic performance
- Depression
These are not all the symptoms of obstructive sleep apnea. Some of these symptoms may indicate another disease or condition. Only a doctor can diagnose obstructive sleep apnea. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis is made by a pediatric pulmonologist or ear, nose, and throat (ENT) specialist and involves an overnight sleep study (polysomnography).
Treatment may include surgery to remove the adenoids and/or tonsils, use of continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), and/or oxygen therapy. In rare cases, facial or jaw surgery may be considered. It is important to consult with a skeletal dysplasia expert before pursuing this option.
Sweating
(3 to 5 years)
What is it?
Excessive sweating (also called perspiration), which may be worse during sleep.
Possible symptoms
- Damp or wet skin, hair, clothing, and/or bed sheets
How is it managed?
Formal diagnosis is not typically needed. Usually observed by parents at home.
Medical treatment is not typically needed. Parents may dress the child in light, breathable clothing and blankets at night to help reduce sweating at night. If sweating is related to sleep apnea, a pediatric pulmonologist may be involved in treatment.
Most sweating, especially during sleep, does not indicate a serious medical problem. However, if the child is sweating while eating and/or having trouble breathing when they sleep, they should have an overnight sleep study (polysomnography).
Limited elbow and hip extension
(3 to 5 years)
What is it?
Limited ability to straighten the arm at the elbow joint and/or limited motion of the hip when moving the leg forward and backward (also called joint contracture).
Possible symptoms
- Limited movement in the affected joints
- Restricted arm reach
These are not all the symptoms of joint contracture. Some of these symptoms may indicate another disease or condition. Only a doctor can diagnose joint contracture. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis is made by a pediatric orthopedic specialist/surgeon.
Treatment is given by a physical and/or occupational therapist. An occupational therapist can help with adaptations for restricted arm reach. A physical therapist (or a pediatric orthopedic specialist/surgeon) can provide exercises to help with limited hip extension.
Loose joints
(3 to 5 years)
What is it?
Increased range of motion in the joints (also called joint hypermobility), most commonly in the knees and fingers.
Possible symptoms
- Difficulty walking
- Bowing of the knee when weight is put on it
- Chronic pain
- Delayed development of self-care skills (for example, toileting or dressing)
These are not all the symptoms of hypermobility. Some of these symptoms may indicate another disease or condition. Only a doctor can diagnose hypermobility. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis is made by a pediatric orthopedic specialist/surgeon following physical examination.
Treatment is given by a physical and/or occupational therapist, who will identify ways to increase mobility and provide support skills for daily life.
Bowed legs
(3 to 5 years)
What is it?
- Bowing at the knees or lower legs (also called genu varum)
- Occurs in about 4 in 10 children with achondroplasia
- Typically starts to develop as the child begins to stand and may get worse over time
Possible symptoms
- Bowing at the knees or lower legs when standing or walking
- Differences in walking (including instability)
- Knee or lower leg pain
Only a doctor can diagnose genu varum. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis is made by a pediatric orthopedic specialist/surgeon using clinical measurements, gait analysis, and X-rays.
Treatment if needed, involves surgery to align the leg bones. About 20% of people with achondroplasia will need surgery for bowed legs within their first decade of life. Ask your doctor about the availability of specialists who have experience performing this procedure in people with achondroplasia.
Ear infections or fluid buildup
(3 TO 5 YEARS)
What is it?
Fluid in the middle ear that may or may not occur with an infection (also called chronic or recurrent otitis media or otitis media with effusion). Affects more than 25% of children with achondroplasia.
Possible symptoms
- Ear pain and/or discharge
- Difficulty hearing
- Language delay
- Fever
- Vomiting
- Clumsiness
- Disturbed sleep
These are not all the symptoms of chronic or recurrent otitis media or otitis media with effusion. Some of these symptoms may indicate another disease or condition. Only a doctor can diagnose these conditions. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis is made by a pediatrician or an otolaryngologist (ear, nose, and throat [ENT] specialist) using a device called an otoscope to look inside the child’s ear.
Treatment is typically provided by an otolaryngologist/ENT specialist and may include
- Antibiotics (for severe, persistent, or recurrent infections)
- Ear tubes to help drain fluid and prevent infections*
- Surgery to remove adenoids, which are glands in the back of the nose to help internal ear drainage
- Hearing aids, if your child has hearing loss that is not helped by surgery or affects their learning or daily functioning
*Note: For children with achondroplasia, ear tube insertion should ideally be performed by a provider familiar with their unique ear and airway anatomy.
Dental problems
(3 TO 5 YEARS)
What is it?
Development of the facial bones may lead to sticking out of the lower jaw and an underdeveloped upper jaw. These changes can cause narrowing of the roof of the mouth (palate) and dental problems.
Possible symptoms
- Overcrowding of teeth
- Open bite
These are not all the symptoms of dental problems. Some of these symptoms may indicate another disease or condition. Only a dentist can diagnose dental problems. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis involves examination by a dentist or orthodontist.
Treatment includes routine dental care by a general dentist. Orthodontic care, including braces and expansion of the palate, may be needed.
Reflux
(3 TO 5 YEARS)
What is it?
Stomach contents (food and drink) come back up into the esophagus, or tube between the throat and the stomach (also called gastroesophageal reflux disease [GERD]). May cause breathing problems.
Possible symptoms
- Regurgitation or vomiting
- Noisy breathing
- Chronic coughing and wheezing
- Irritability
- Poor appetite
- Trouble sleeping
These are not all the symptoms of reflux. Some of these symptoms may indicate another disease or condition. Only a doctor can diagnose these conditions. If you have any questions about what your child is experiencing, please talk to their health care provider.
How is it managed?
Diagnosis is made by a pediatric gastroenterologist or pediatric pulmonologist and typically involves taking a medical history and testing. Tests may include endoscopy and/or monitoring of esophageal acid (pH monitoring).
Treatment may include diet modifications and medication.